Seamless hosiery machine



Feb. 27, 1968 c. A. TONKlN SEAMLESS HOSIERY MACHINE Filed Sept. 12. 1960 5 r Y mV Rh N 00 R TT 0 N 7 EW M V mm IA 5 E m V HE C United States Patent 3,370,442 SEAli ILESS HGSilERY MACHINE Charles Albert Toninin, Ivanhoe, Victoria, Australia, as-

signor to Nagata Seiki Company Limited, T oshima-ku, Tokyo, Japan Fiied Eept. 12, 1960, Ser. No. 55,265 Claims priority, application Australia, Sept. 16, 1959, 52,820/59 5 Claims. (Q1. 66-55) This invention relates to seamless hosiery produced upon circular knitting machines, and is particularly directed to the production of ladies stockings.

It has long been recognised that seamless stockings and the method of manufacture have a number of disadvantages, the principal one being the irregularity in the overall length of the stocking and the resultant frequency of rejects or seconds in a batch run of stocking, notwithstanding the use of skilled operatives.

Stockings of irregular length and varying proportional lengths in the feet, ankle and panel or leg of the stocking not only affects the length or size of a stocking but creates color variations, and shades which also causes rejection apart from the irregularity of size.

The variation of length in the foot or leg to upset the particular proportions in the size selected for the knitting of a particular batch arises from variation in the degree of tightness of the knitting, and the control of the tightness has hitherto been determined solely by the skill of the operative controlling the machine. Having regard to the difiiculty of assessing the measurements of the somewhat elastic knitted fabric and determining the proportion of adjustment to be joined to each source of stitch length, the control of hosiery lengths is an arduous event to a skilled operative.

It is the principal objective of the present invention to provide an improved and effective method for the production of seamless hosiery upon a circular knitting machine to positively control the length of the stockings produced, without the requirement or attention of skilled labour during the production of a batch of stockings of selected size.

It is a further objective of the invention to provide by the abovementioned method an effective control over the length of stitch to ensure that the relative proportional lengths of the foot, ankle, and leg or panel of the stocking remains substantially constant in the selected number of stockings.

With the above stated principal objective in view, the method according to this invention consists essentially in controlling the proportions of an article of hosiery knitted upon a circular knitting machine comprising controlling the nominal length or" stitch of the main yarn during knitting cycle by a single gradation cam having a profile determined by the required proportion of the article, that is during the knitting of the leg, calf-stiffening, ankle and the foot.

More specifically there is provided a method of controlling the overall length and proportions of an article of hosiery knitted upon a circular knitting machine comprising controlling the length of the stitch of the main yarn during the knitting cycle by a single gradation cam having a profile determined by the required proportions of the article, checking the overall length of the article at a predetermined point in the knitting cycle against the correct overall length at that point and adjusting the nominal length of stitch by a fixed predetermined amount throughout the remainder of the knitting cycle of the machine, the direction of said adjustment depending upon whether the article is greater or less than the correct length at that point.

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Thus, the overall length of the leg is controlled by one initial adjustment and the proportional size of the foot, is also controlled responsive to this adjustment, the latter being knitted somewhat tighter than the first portion of the leg.

According to the method the proportion of the stiffening or tightening of the stitch length in the ankle and foot, relatively to the main panel or first part of the leg is predetermined and controlled by the shape or contour of the stitch regulation and gradation cam.

By the use of the above cam in a number of machines, each of the latter will knit exactly the same proportions in length of leg, calf, ankle and foot.

Accordingly, upon the number of courses in each part of the stocking being determined, the machine will produce a stocking with the foot exactly on size when the leg length is correct, and if the leg length is long then the foot size is long, and vice versa.

As the leg length is much more easily determined than the foot and the conventional foot proportion to the leg is 1:6 to 1:8, the foot measurements can be ignored and the stocking length can be readily adjusted when only one setting screw co-active with the abovementioned cam is involved.

The stitch gradation cam can also be shaped or contoured so as to impart a knitting characteristic to the stocking whereby the angle is tighter than the foot thus enhancing its fitting to the human leg more accurately, and appearance to constitute a feature of the instant invention.

This shape in the stocking also materially assists in the matching of the knitting just prior to, and immediately after the knitting of the heel pouch, when the friction of moving the cylinder slowly by the conventional gradation cam and suddenly from oil the heel regulator often results in a change of knit at this point in the knitting operation.

When only one adjusting screw is use-d in operation with the above single cam to control the entire overall length involving the main yarn according to the described method, then power operated adjustment can be made during the knitting operation, the direction of adjustment being determined by the length of the stocking being knitted at the time.

To that end assuming the stocking being knitted is long, then the above adjusting screw will tighten the stitch for the next stocking to be knitted and conversely if the stocking is short, the stitch will be loosened, and provided the stocking is within predetermined limits, then no adjustment would be made.

This stitch control is automatic whereby the stockings will be knitted at all times substantially uniformly as to length with rectification being affected for any slightly irregular lengths in the leg and foot of the stocking.

The stitch adjustment screw may be set relatively to the above cam, mechanically, electronically, hydraulically or pneumatically.

For instance adjustment may be made by the mechanism being activated by the breaking of an electronic beam or beams by the welt or other portion of the stocking by virtue of its gravitational or assisted length whilst being knitted.

The invention will be more readily understood from the following description of a practical arrangement of a circular knitting machine adapted to operative in accordance with the method of the present invention and illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a diagrammatic representation of a circular knitting machine of the suction take-up type incorporating the present invention,

FIG. 2 is a perspective view of the stitch regulation and gradation cam and lever as used in the machine shown in FIG. 1,

FIG. 3 is a perspective view of the servo mechanism to adjust the gradation cam tappet,

FIG. 4 is a graphical representation of the profile of the regulation and gradation cam; and

FIG. 5 is a circuit diagram showing a circuit for the apparatus.

Referring now to FIG. 1 the sinker cap 6 contaming the sinkers 5 is attached to the cylinder 7 which is supported by a plate 8a carried by the fabric tube 8. The needles reciprocate relative to the sinkers to effect the knitting of the yarn and are guided in grooves 9 in the cylinder 7. The nominal length of the stitch of the knit is determined by the relative position of the sinker to the co-operating needle when the latter is at the lower end of its stroke.

The stitch regulating lever or rocker 10 is pivoted to the frame of the machine for angular movement about axis 11 and engages the stitch gradation cam 13 through the screw tappet 12. The arm 14 on the regulating lever 10 engages the master screw 15 provided in the lug 17 on the fabric tube 8. A limit screw 19 is also provided on the fabric tube to engage the frame of the machine.

Mounted on the machine frame adjacent to the screw tappet 12 is the bracket 20 supporting two solenoids 21 and 22. The cores 23 and 24 of the respective solenoids each carry a pawl 25 and 26 respectively as shown in FIG. 3. The pawls 25 and 26 engage ratchet toothed wheels 27 and 28 respectively which are mounted on shaft 30 journalled in the bracket 20. The pawls are arranged to engage their respective ratchet toothed wheels on opposite sides of the axis of the shaft 30. Thus if solenoid 21 is energized pawl 25 engages ratchet toothed wheel 27 and effects a part rotation of the latter in a clockwise direction. Conversely if solenoid 22 is energised ratchet toothed wheel 28 is partially rotated in an anti-clockwise direction.

The tongue 31 on the shaft 30 engages the slot in the head 32 of the screw tappet 12 so that the latter is screwed in or out of the regulating lever 10 depending upon which solenoid is energised.

In the vacuum take-up type of machine as shown the stocking as' it is knitted is drawn down the take-up tube by a suction applid thereto. The take-up tube is made of transparent material and the length of the stocking at a given point in the knitting cycle is checked by a scanning or a comparator device comprising two photo-electric cell units 51 and 52.

Each unit contains a light source which throws a beam of light through the take-up tube on to the mirror 53 which reflects it back to impinge on the photo-electric cell. The solenoids 21 and 22 are controlled by switch means in the form of relays which, as shown in FIG. 5, are arranged in circuit with the photo-electric cell units 51 and 52 so that if neither beam is broken, i.e., the stocking is short, solenoid 21 is energised, and if both beams are broken, i.e., the stocking is long then solenoid 22 is energised.

So that the solenoids will only be operated at the correct point in the knitting cycle, a master-switch 54 is provided, as shown schematically in FIG. 4 and in detail in FIG. 5, to supply current to the terminal of the relay at the selected point in the knitting cycle. The master switch energizes both light sources, and supplies power to the terminals of the relay.

The photo-cells and the master switch are arranged so that it is the welt fabric of the stocking which is utilized to obscure the light source from the photo-cells when the length check is being made and as the stocking is in a tubular form and the welt is of double fabric thickness, 4 layers of fabric act to obscure the light source. The photo-cells are of such sensitivity that only two layers of fabric is sufficient to cause the unit to function. Thus,

should a flaw appear in one or even two layers of the fabric, the control of the length will not he lost due to the multiple layers of fabric involved.

The circuit of FIG. 5 includes relays 60 and 63, the relay 60 closing a normally open relay switch 61 in the circuit from the power source through the switch 54 to the solenoid 21 and opening a normally closed relay switch 62 in the circuit from the power source through the switch 54 to the solenoid 22. The relay 60 is energized by the action of the light receiving element 65 in the photo-electric cell unit 51. The unit 51 also includes a lamp 66 for providing light which is reflected ofif refiector 53, the lamp being energized from the power source also through the switch 54.

The circuit also includes a relay 63 coupled to light receiving element 67 in the unit 52, and opening a normally closed switch 64 in the circuit from the power source to the solenoid 22. Lamp 68 in the unit 52 is also coupled to the power source.

When a stocking decending through the tube 50 is too short, both elements 65 and 67 will have light impinging thereon, and both relays 6t} and 63 will be energized. Normally open switch 61 will therefore close, thus energizing coil 21, while switch 62 will open preventing the energizing of coil 22.

When the stocking is the right length, the reflected light will not strike element 65, and thus switch 61 will remain open and switch 62 will remain closed. Light will strike element 67, thus opening switch 64, and preventing coil 22 from being energized.

When the stocking is too long, neither element 65 nor element 67 will have light impinging thereon, and the circuit will be as in FIG. 5, with only coil 22 energized.

FIG. 4 shows in graphical form a typical profile for the regulation and gradation cam. The graph represents the variation in radius of the cam relative to the base circle. Section 1-2 of the profile is concentric with the base circle and corresponds to the leg portion of the stocking. Section 23 corresponds to the leg stiffening portion of the stocking during which the cam progressively decreases in diameter resulting in a gradual tightening of the knit. During the knitting of the ankle portion the cam is of constant radius as represented by 3-4. There is a slight increase in radius from 4 to 5 so that there is an even blending of the knit from the ankle to the slightly looser foot portion. Section 56 controls the stitch length for a few courses prior to the knitting of the heel and all the foot portion. During the section 6-7 the radius increases rapidly to reduce the knit tension from the foot to that required for the leg in readiness for the knitting of the next stocking.

The profile of the regulation and gradation cam can be selected to suit the required relation between the proportions of the leg, leg stiffening, ankle and foot. Thus all machines having a cam of the same profile will produce stockings having the same proportions and with the overall length controlled as before described, there will be substantially no reject stocking produced.

In the foregoing the regulation and gradation cam has controlled the proportions of the stocking, and the screw tappet associated therewith has controlled the overall length of the stocking. However, it is to be understood that the mechanism used to adjust the screw tappet can also effectively control the overall length of the stocking by effecting adjustments to other elements of the machine. The mechanism can be used to raise and lower the stitch cam, or to move the sinker cam in and out.

The mechanism may also be used to adjust the overall length by varying the tension on the yarn which can be effected by any of the known means such as disc tension, gate tension, and the like.

I claim:

1. In a circular knitting machine of the vacuum takeup type having a transparent take-up tube, means for controlling the overall length and proportions of an article of hosiery being knitted comprising the combination of a gradation cam having a profile determined by the required proportions of the article to be knitted and rotated in time relation with the knitting cycle of the machine, means operable by the gradation cam to effect relative axial movement between the sinkers and the needles to efiect proportional variations in the length of the stitch of the main yarn from a nominal length during the knitting cycle, two photo-electric cell devices, two independent light sources to pass beams of light transversely through the take-up tube of the machine at a predetermined point along the length thereof to activate the respective photo-electric cell devices, switch means connected to said light source and adapted to connect the light source to a power supply to energise said light sources at a predetermined point in the knitting cycle, and an adjuster operable by said photo-electric cell devices so as to increase the nominal stitch length a fixed predetermined amount throughout the remainder of the knitting cycle if neither of the beams of light are broken by the article being knitted and to decrease the nominal stitch length by a similar amount if both beams of light are broken by said article.

2. The combination as claimed in claim 1 wherein the means operable by the gradation cam comprises a rocker pivotally mounted on the machine frame and the rocker operatively engages the sinker cap carrying the sinkers to axially move the latter relative to the needles in response to the rotation of the cam, the rocker having a threaded tappet screw attached thereto to contact the profile of the cam, and said stitch length adjuster comprises a pair of coaxial toothed wheels rotatably supported by the frame and each drive coupled to the tappet screw, a pair of fingers one engaging the teeth on each wheel, a pair of solenoids one coupled to each fingers and so arranged that upon energising one solenoid the tappet screw is rotated in a first direction to raise the sinkers and upon energising the other solenoid the tappet is rotated in a second direction to lower the sinkers, and switch means operated by the photo-electric cells to selectively energise one solenoid if the length of the article is less than the required length and to energise the other solenoid if the article is greater than the required length, said photo-elec tric cell devices being arranged in circuit with the solenoids so that if neither beam is broken the solenoid will be energised to rotate the tappet screw in the first direction and if both beams are broken the other solenoid will be energised to rotate the tappet screw in the second direction.

3. In a circular knitting machine of the vacuum takeup type having a transparent take-up tube, means for controlling the proportions and overall length of the article of hosiery being knitted comprising; a gradation cam having a profile determined by the required proportions of the article to be knitted and rotated in timed relation with the knitting cycle; means operable by the gradation cam to eitect relative axial movement between the sinkers and the needles of the machine to effect proportional variations in the length of the stitch of the main yarn from a nominal length during the knitting cycle; a comparator device comprising two photo-electric cell devices, a light source to pass two independent beams of light transversely through the take-up tube of the machine at predetermined points along the length thereof to activate the respective photoelectric cell devices, and switch means connected to said light source and adapted to connect the light source to a power supply to energize said light source at a predetermined point in the knitting cycle; and an adjuster operable by said photo-electric cell devices to vary the nominal length of stitch by a fixed predetermined amount throughout the reminder of the knitting cycle subsequent to the time of sensing by said comparator device if neither or both of the beams of light are broken by the article being knitted so that the article will have a length closer to the required length, the variation in the nominal length of stitch being in a direction to increase the length of the article if neither beams are broken and in the opposite direction if both beams are broken.

4. In a circular knitting machine, means for controlling the overall length and proportions of an article of hosiery being knitted comprising in combination; a gradation cam having a profile determined by the required proportions of the article to be knitted and rotated in timed relation with the knitting cycle of the machine; means operable by the gradation cam to effect relative axial movement between the sinkers and the needles to efiect proportional variations in the length of the stitch of the main yarn from a nominal length during the knitting cycle and comprising a rocker pivotally mounted on the machine frame and operatively engaging the sinker cap carrying the sinkers to axially move the latter relative to the needles in response to the rotation of the cam, the rocker having a threaded tappet screw attached thereto to contact the profile of the cam; a comparator device to compare the actual length of the article with the required length at a predetermined point in the knitting cycle; and an adjuster operable by the comparator device if the actual length is beyond predetermined limits to effect a fixed predetermined additional relative axial movement between the sinkers and needles to compensate for the error in length of the article, said adjuster comprising a pair of coaxial toothed wheels rotatably supported by the frame and each coupled to the tappet screw, a pair of fingers one engaging the teeth on each wheel, and a pair of solenoids one coupled to each finger and arranged so that upon energising one solenoid the tappet screw engaged thereby is rotated in a first direction to raise the sinkers and upon energising the other the tappet is rotated in a second direction to lower the sinkers, the additional relative axial movement between the sinkers and needles being completely independent of the movement in response to the rotation of the gradation cam; and switch means operated by the comparator device to selectively energise one solenoid if the length of the article is less than the required length and to energise the other solenoid if the article is greater than the required length.

5. In a circular knitting machine, apparatus for accurately controlling the overall length of tubular fabric produced on the circular knitting machine comprising a scanning device operable to gauge the length of the knitted fabric in relation to a predetermined length, a stitch length control mechanism for selectively regulating stitch length and means operatively connecting said scanning device to said stitch length control mechanism to effect actuation of said stitch length control mechanism to vary stitch length when the length of the knitted fabric varies from said predetermined length.

UNITED STATES PATENTS References Cited 2,856,764 10/1958 Carden 66l46 2,474,894 7/1949 Gottschalck 6655 X 2,972,875 2/1961 St. Pierre 66150 2,995,914 8/1961 Imboden 66150 2,220,807 11/ 1940 Stout et al. 66825 2,516,535 7/1950 Stack 66l46 2,685,786 8/1954 Stack 6655 2,839,907 6/1958 Butler 6655 FOREIGN PATENTS 543,096 5/ 1956 Italy. 582,349 9/1958 Italy. 1,145,977 11/1957 France.

WILLIAM CARTER REYNOLDS, Primary Examiner. 

1. IN A CIRCULAR KNITTING MACHINE OF THE VACUUM TAKEUP TYPE HAVING A TRANSPARENT TAKE-UP TUBE, MEANS FOR CONTROLLING THE OVERALL LENGTH AND PROPORTIONS OF AN ARTICLE OF HOSIREY BEING KNITTED COMPRISING THE COMBINATION OF A GRADATION CAM HAVING A PROFILE DETERMINED BY THE REQUIRED PROPORTIONS OF THE ARTICLE TO BE KNITTED AND ROTATED IN TIME RELATION WITH THE KNITTING CYCLE OF THE MACHINE, MEANS OPERABLE BY THE GRADATION CAM TO EFFECT RELATIVE AXIAL MOVEMENT BETWEEN THE SINKERS AND THE NEEDLES TO EFFECT PROPORTIONAL VARIATIONS IN THE LENGTH OF THE STITCH OF THE MAIN YARN FROM A NOMINAL LENGTH DURING THE KNITTING CYCLE, TWO PHOTO-ELECTRIC CELL DEVICES, TWO INDEPENDENT LIGHT SOURCES TO PASS BEAMS OF LIGHT TRANSVERSELY THROUGH THE TAKE-UP TUBE OF THE MACHINE AT A PREDETERMINED POINT ALONG THE LENGTH THEREOF TO ACTIVATE THE RESPECTIVE PHOTO-ELECTRIC CELL DEVICES, SWITCH MEANS CONNECTED TO SAID LIGHT SOURCE AND ADAPTED TO CONNECT THE LIGHT SOURCE TO A POWER SUPPLY TO ENERGISE SAID LIGHT SOURCES AT A PREDETERMINED POINT IN THE KNITTING CYCLE, AND AN ADJUSTER OPERABLE BY SAID PHOTO-ELECTRIC CELL DEVICES SO AS TO INCREASE THE NOMINAL STITCH LENGTH A FIXED PREDETERMINED AMOUNT THROUGHOUT THE REMAINDER OF THE KNITTING CYCLE IF NEITHER OF THE BEAMS OF LIGHT ARE BROKEN BY THE ARTICLE BEING KNITTED AND TO DECREASE THE NOMINAL STITCH LENGTH BY A SIMILAR AMOUNT IF BOTH MEANS OF LIGHT ARE BROKEN BY SAID ARTICLE. 